Electrical insulation
Electrical insulation and dielectric materials includes various forms of materials that surround and protect electrical conductors and prevent unwanted current flow, leakage or crosstalk. Electrical specifications include electrical resistivity, dielectric strength, and dielectric constant. Resistivity is the longitudinal electrical resistance (ohm-cm) of a uniform sample of unit length and unit cross-sectional area. Dielectric strength is the maximum voltage field that electrical insulation and dielectric materials can withstand before electrical breakdown occurs.
Electrical insulation and dielectric materials are available in many different material forms. Choices include adhesives, bar stock, blankets or batts, blocks, braided products, casting resins, ceramic or inorganic materials, coatings, composites, and dielectric coatings. Adhesives require clean surfaces for joining. Bar stock usually has a square cross-section; however, stock forms in other shapes are also available. Blankets or batts (batting) are made of thick layers of woven and/or non-woven fabric sheets. Blocks are building materials or masonry units that have a rectangular shape. Braided electrical insulation and dielectric materials are suitable for thermal insulation fabrics.
Material forms for electrical insulation and dielectric materials include fabricated parts and shaped stock, film or sheet, flat or bar stock, gap filling sealants, greases and gels, hollow or tubular stock, fluids, and knitted products. Lubricants, metal working fluids, molding compounds, non-woven products, plates or boards, and polymers are also available. In addition, electrical insulation and dielectric materials may come as potting compounds, powders or grains, precursors, rock stock, rope or cordage, roving or yarn, sleeves or warps, sputtering targets, tapes, tiles, varnishes, wafers, webbing, and woven products.
Electrical insulation and dielectric materials are used in a variety of applications and industries. Some products are used in electronics or semiconductors, electrical power products or high voltage (HV) applications, glazes and protective coatings, or flame retardant materials. Electrical insulation and dielectric materials may also be metalized or compliant with MIL-SPEC standards. Single crystal materials and electrical insulation and dielectric materials that meet standards from Underwriters Laboratories, Inc. (UL) are also available. Specialized products are depending upon the configuration of the conductor and the application. Examples include the line straps in a circuit breaker or wiring.